A standard spinning or twisting machine has a horizontally elongated spindle bank or beam on which is supported a row of equispaced and parallel spindles rotatable about respective upright axes defining a vertical plane. Each spindle can be powered as described in U.S. Pat. Nos. 630,567 of Sawyer and 4,817,371 of Wolf, in German patent documents 548,109, 819,660, 3,727,939, 3,912,370, and 4,106,953, and in Italian patent 3,358,378 by a respective electric motor. The advantage of this is that it is possible to provide some degree of individualized control for each spindle. To do this each motor must be provided with its own electrical control circuit.
Thus in the standard system a plurality of electrical-supply conductors extend the full length of the spindle beam and are connected at each spindle assembly to the respective control circuitry. In turn this circuitry is of course wired to the respective motor.
When trouble develops with one spindle it is frequently necessary to deenergize the entire spindle bank so as to be able to work on the nonfunctional spindle control circuit while same is not energized. This leads to substantial losses in production, but is necessary to be able to safely disconnect a control circuit or trouble-shoot it. Normally a substantial housing must be removed to reveal the control circuits of the spindle bank, then the individual module is worked on.
Even though above-cited Italian 358,378 and German 4,106,953 propose individual cutoff switches for the spindle motors and control circuits, it is still frequently necessary to shut down the entire bank to actually work on a single part of it, in particular when it must be disconnected and replaced which is normally all that the machine operators do.